Question: Rewrite as a simplified fraction. ${3.2\overline{21} = {?}}$
Explanation: Let $x$ equal the decimal. Set up two equations such that the digits after the decimal point are identical. ${\begin{align*}1000x &= 3221.2121...\\ 10x &= 32.2121...\end{align*}}$ Subtracting the two equations, we have: ${990x = 3189}$ ${x = \dfrac{3189}{990}} $ ${x = \dfrac{1063}{330}} \text{or} {3 \dfrac{73}{330}}$